Metals have been known to catalyze many different kinds of chemical reactions, and have been prepared in a variety of physical forms for that purpose.
Specifically, platinum, palladium, iridium, rhenium, nickel, iron, copper, and various other metals have been used to catalyze a variety of reactions.
Nickel is particularly useful in the form of "Raney nickel" for catalyzing the hydrogenation of fats and various other purposes. It is produced by alloying nickel and aluminum, and dissolving most of the aluminum with alkali solution, to produce catalysts of porous metallic nickel.